The present invention relates to a storage apparatus for storing digital signals such as a digital video signal and a digital audio signal, and a shockproof case for the storage apparatus.
In recent years, an apparatus for recording and playback a digital video signal and a digital audio signal has been used in many ways. Particularly, in an audiovisual field for a professional service, for example, a portable type audiovisual apparatus equipped with a computer has been used for news coverage generally. In addition, data (digital signals) of the news coverage have been often processed and edited with the computer of the portable type audiovisual apparatus. This is because such digital signals do not degrade by duplication, and are easily processed on the computer.
Meanwhile, a storage apparatus for storing the above-mentioned video and audio signals, for example, a fixed magnetic disk apparatus (hereinafter, referred to as an "HDD") has an increasingly larger storage capacity and an increasingly faster speed for recording and playback data. More specifically, in the case of a 3.5 inch HDD, for example, the 3.5 inch HDD having the storage capacity of 10.times.10.sup.9 bytes is being made practical. It is expected that the storage capacity of this 3.5 inch HDD will be larger 1.6 time every one year.
As the storage capacity of the HDD increases, the HDD is used as the recording and playback apparatus for the above-mentioned video and audio signals in more various audiovisual apparatuses. Furthermore, in the case that the HDD is used as a detachable recording and playback apparatus from the portable type audiovisual apparatus, it is expected to realize functions which were impossible to availe with a conventional tape-type storage apparatus, through utilization of a high speed and random accessibility of the HDD. Concretely, in such audiovisual apparatus, it is expected to realize a realtime non-linear field editing function and a pre-recording function which allows to record a few seconds ahead of pressing of a record button.
However, it is known that the HDD has the following characteristics (1) through (3):
(1) A magnetic head floats up an extremely short distance of few hundreds angstroms from a surface of a recording medium during an operating state. PA1 (2) The magnetic head moves relative to the recording medium, following information tracks each having a width of few microns, thereby recording or playback the signal. PA1 (3) The magnetic head is in a direct contact with the recording medium at a non-operating state. PA1 storage means, PA1 holding means disposed around the storage means and for holding the storage means, PA1 a protection box for containing the storage means and the holding means, and PA1 a supporting member disposed between the holding means and the protection box, and the supporting member for supporting the holding means to the protection box elastically. PA1 the supporting member is disposed between the box frame and the protection box, the supporting member is fixed to one of the box frame and the protection box, and supporting member elastically supporting the box frame in the protection box. PA1 the supporting member is disposed between the box frame and the protection box, the supporting member is fixed to one of the box frame and the protection box, the supporting member elastically supporting the box frame in said protection box. PA1 holding means disposed around storage means to be held, the holding means fixed to the storage means, PA1 a protection box for containing the storage means and the holding means, and PA1 a supporting member disposed between the holding means and the protection box, and the supporting member elastically supporting the holding means to the protection box.
Hence, if the HDD receives an impact force applied directly to the audiovisual apparatus or an external shock as the HDD is accidentally dropped during being transported, attached or detached from an assembled set, there is a possibility that the signal is not recorded or reproduced exactly. Further, the magnetic head damages the recording medium, so that there is a problem that data (information) are lost in the damaged portion of the recording medium. Still further, the magnetic head itself may be destroyed.
Accordingly, in the audiovisual apparatus equipped with the HDD, it is important to ensure the reliability of the HDD. In particular, in the case that the HDD is used as the recording and playback apparatus of the portable type audiovisual apparatus, it is strongly required to guarantee the shockproofness of the HDD.
With regard to the aforementioned problems, U.S. Pat. No. 5,253,129 discloses a conventional shockproof supporting apparatus for a detachable HDD.
The conventional shockproof supporting apparatus will be explained with reference to FIGS. 8 and 9 concretely.
FIG. 8 is an exploded perspective view showing a conventional shockproof supporting apparatus for an HDD, and FIG. 9 is a cross sectional view showing an internal structure of the conventional shockproof supporting apparatus shown in FIG. 8.
As shown in FIGS. 8 and 9, a conventional HDD pack 30 comprises a head disk assembly (hereinafter, referred to as an "HDA") 31 formed into a box shape, and a protection box 32 for containing the HDA 31. The HDD pack 30 is detachable from an apparatus to which the HDD pack 30 is attached. As shown in FIG. 9, the HDA 31 comprises a plurality of disks 35 which are magnetic recording mediums, a spindle motor 36 for rotating while supporting the disks 35, and a plurality of magnetic heads 37 for recording and playback data. Furthermore, the HDA 31 has arms 38 for supporting the respective magnetic heads 37, an actuator 39 for positioning the magnetic heads 37, and a box frame 40 shaped as a rectangular parallelopiped for containing the above-mentioned elements. A supply of an electric power to the HDA 31 and a signal transfer between the HDA 31 and the apparatus attaching to the HDD pack 30 are realized through a connector (not shown) fixed to the box frame 40.
The protection box 32 is configured with a top plate 32a, a frame member 32b and a bottom plate 32c, and thereby is formed into a rectangular parallelopiped shape. A plurality of supporting members 33 and a plurality of pad members 34 for the respective supporting members 33 are disposed between HDA 31 and the protection box 32. Each of the pad members 34 is fixed at a predetermined position in an outer surface of the box frame 40, and the supporting members 33 are fixed to the pad members 34, respectively. When the HDA 31 is contained in the protection box 32, each of the supporting members 33 comes in contact with an inner surface of the protection box 32, and thereby to support the HDA 31 shockproof.
As has been explained in the above, in the conventional HDD pack 30, a plurality of the supporting members 33 are disposed between the HDA 31 and the protection box 32, so as to realize the shockproofness and a buffering effect in the support members 33.
However, in the conventional shockproof supporting apparatus, it was assumed that the HDD pack 30 was integrated with the computer principally. Therefore, in the case that the HDD is used as a detachable storage apparatus for the portable type audiovisual apparatus, the HDD is required to be resistant to a large impact force applied when the portable type audiovisual apparatus is hit against an obstacle and the like, or an external shock applied while the HDD is carried around.
In general, the HDD can bear an impact acceleration of about 300 G at the non-operating state. However, for instance, if the HDD is dropped onto a tile floor from the height of 76 cm, the impact force upon the HDD is 1,500 G or larger. Further, when the portable type audiovisual apparatus records or reproduces while moving, the impact force upon the portable type audiovisual apparatus may reach as much as maximum 10 G in some cases. Even when in such a condition, the HDD integrated in the portable type audiovisual apparatus must be able to perform reliable recording and reproduction without having data lost or damaged.
Accordingly, in the case that the HDD is used as the detachable storage apparatus for the portable type audiovisual apparatus, it is required that the HDD pack must have a structure which makes it unlikely that the HDD is dropped. Further, even if the detachable storage apparatus (the HDD) is dropped by mistake while transported or replaced, the HDD pack must have the shockproofness so that data will not be lost or damaged in the HDD. In addition, the HDD pack needs be as small as possible to an extent that the portability is not sacrificed.